Here is a summary of the click exchanges which have been mentioned in previous threads:Idarionis HydraUtopia Click ExchangeAutoclicks (in French, follow the English link for pages in English)Yarolds (no information about this is available until you create an account)

Also on Idarionis Hydra, msattler runs 'Team Seti':
If you are not on a team there and would like to join him, you would be most welcome. Team members can receive extra visits, either by changing their IP address or by drinking from the Youth Fountain as a single-IP user.

Soooooo....
The kitties invite you to join them on 'Team Seti'.

Meow meow.

If you use Firefox (and in some cases related browsers,) the following add-ons are relevant:Flashblock: replace Flash content by buttons -- reduces mini-city page load times;Cookiewhitelist: cookie management -- otherwise you will have thousands of extra cookies cluttering up your browser;NoScript: JavasScript etc management -- decide which sites may or may not execute JavaScript;LeechBlock: block particular sites completely -- avoid sites you do not wish to supportBetterPrivacy: delete Flash supercookies -- recommended by The Dreamer.

The featured mini-cities are:Seti City: this is "the" seti@home mini-city created for us all (and of course our kitties) by msattlerDvorakSociey: created for Antonin by KWSN Ekky Ekky Ekky.Skofus: this was a Ruined City adopted and rescued in true Nevil Shute fashion by Uli.Dacomville: Sirius B's mini-city.UAE Residents: Whiskey's mini-city.Ariz Moon City: Miss Moon's mini-city.Eagle's Flight: created by the still extremely stealthy Mr Eagle.rwrwton: Bill's mini-city.SETI.USA, TFFE, KWSN: cities for the corresponding teams.
Utopia ref: used to receive clicks from Utopia only, as a result of a single account using one IP address, currently not being updated.